Prefabricated concrete support mechanism for a railroad track with integral rubber boot and method of manufacture

ABSTRACT

A precast, concrete slab rail system is provided which includes a resilient boot positioned around at least one rail, and which can be reversibly installed or removed from the concrete slab without the use of attachment hardware or destruction of the concrete slab.

FIELD OF THE INVENTION

[0001] The present invention relates to a rail support mechanism usedfor railroad mass transit roadway intersections, street running trackand more specifically precast concrete structures with a removablerubber boot assembly.

BACKGROUND OF THE INVENTION

[0002] Existing rail support structures for mass-transit or railroadsystems typically utilize timber or cast-in-place construction that isboth relatively expensive to construct and difficult to repair. Moreparticularly, where time consuming timber construction is not used,construction is often preformed using cast-in-place methods, which arealso time consuming and therefore, expensive. Thus, there exists a needto minimize the time at the construction site. In addition, forcast-in-place systems, current rail replacement techniques typicallyinvolve using a jack-hammer to chip away the concrete in the vicinity ofthe rail that is to be replaced. This technique is both time consumingand expensive, and exposes the rail line, construction crew and anyassociated railroad or nearby automobile traffic to extended periods ofconstruction repair. Other types of rail support systems have previouslyutilized rubber on polymer boots on sleeves around the rail. However,these systems are generally positioned within the concrete while curing,and are thus not removable, or require attachment hardware to retain theboot in operable position.

[0003] In addition, to the above problems, there is also a need toprovide a rail support apparatus that minimizes noise generated by railcars traversing the rails. Similarly, there exists a need to reduce andminimize vibrations associated with passing rail cars, and thus toimprove the quality of the ride for passengers.

[0004] Finally, there is a significant need for a method of manufactureand construction which can streamline the construction schedule byoffering precast concrete rail support structures that are manufacturedin a controlled environment, can be easily transported to aninstallation, and can be quickly repaired. Thus, the present inventionaddresses these problems and industry needs, as described below.

SUMMARY OF THE INVENTION

[0005] In a first aspect of the present invention, an apparatus isprovide that is a precast slab that includes at least one shaped troughfor receiving a rail and a resilient rail support device. The precastnature of the slab allows the time consuming process of curing theconcrete that forms the slab to occur in a controlled manufacturingfacility. Precast slabs of customized or standardized dimensions canthen be produced at a location remote from the construction site, andsubsequently delivered for speedy installation, thereby reducing thetime and associated cost of having construction crews located at theconstruction site.

[0006] It is another aspect of the present invention to provide acombination resilient rail support device, or boot, that holds the railwithin the precast slab. Proper retention of the resilient boot and railis achieved because the slab is made with a shaped trough that includesa recess with a pronounced shoulder for receiving and engaging apredetermined geometric profile on the resilient boot. Noise andvibration dampening is achieved by isolating the metallic rail withinthe precast slab by surrounding it with the resilient boot. Verticalretention of the resilient boots within the shaped troughs is achievedbecause the lateral recesses of the shaped troughs feature uppershoulders that prevent vertical dislodgement of the resilient boot andrail from the shaped trough during normal rail car operating conditions.The resilient boot also lends itself to easy future repairs of the rail,because the resilient boot can be removed from the precast slab bywithdrawing it using properly sized equipment with the rail intact,thereby eliminating the need to jack-hammer or otherwise remove the railfrom the rail support using difficult, time consuming and expensivetechniques. Thus, in one aspect of the present invention, an apparatusis provided comprising a substantially concrete slab that includes aleast one shaped trough comprising a first lateral recess and having anupper shoulder. The apparatus also includes a resilient boot shaped forinsertion into the shaped trough, the resilient boot including a bottomportion and two side support portions, at least one of the side supportportions including a lateral projection that inserts into the firstlateral recess to impede vertical travel. In addition, the apparatusincludes a rail positioned within an interior opening in the resilientboot, wherein the resilient boot supports the rail when the resilientboot and the rail are installed within the shaped trough.

[0007] In another aspect of the invention, a method is provided formanufacturing the precast slab portion of the precast rail support. Themethod of manufacture includes providing a form with a bock-out thatproperly forms the shaped troughs of the precast slab. The methodincludes providing block-outs with proper projections to create lateralrecesses in the shaped troughs that will then receive the lateralprojections of the resilient boot when the resilient boots and rails areinstalled in the precast slabs at the construction site. Other steps ofthe manufacturing process include placing structural reinforcement inthe form prior to adding concrete to the form, and properly finishingthe surface of the concrete for providing high quality, precaststructural slabs for future placement at the construction site, andwherein the slabs are designed to withstand significant compressiveloads. Thus, in one aspect of the present invention, a method ofmanufacturing a precast slab is provided comprising the steps ofattaching at least one block-out to a precast form, the at least oneblock-out corresponding to a shaped trough in the precast slab, whereinthe at least one block-out includes at least one recess projectioncorresponding to a lateral recess in the shaped trough and also includesa shoulder projection corresponding to an upper shoulder in the lateralrecess of the shaped trough. Additional steps include applying anot-stick coating to the at least one block-out and an interior regionof the precast form, and then adding concrete to the precast form toform the precast slab. Subsequently, additional steps include allowingthe concrete to cure and then removing the at least one block-out andthe precast form to expose the precast slab.

[0008] In yet a separate aspect of the present invention, a method ofinstalling at the construction site is provided by preparing a subgradeto receive the precast slabs. The precast slabs are then lowered ontothe prepared subgrade, and the resilient boots with the rail containedtherein are lubricated and forced downward into the shaped troughs ofthe precast slab. Upon forcing the lubricated resilient boot and railsdownward, the side projections of the resilient boot engage the lateralshoulders of the shaped troughs to hold the resilient boots in placewithout the need for accessory hardware. Thus, in one aspect of thepresent invention, a method for installing a precast rail system isprovided, comprising the steps of preparing a subgrade to receive theprecast rail support apparatus, followed by placing a precast slab ofthe precast support apparatus onto the prepared subgrade, wherein theprecast slab includes at least one shaped trough extending along alongitudinal orientation of the precast slab, and wherein the shapedtrough has a lateral recess that further includes an upper shoulder.Additional steps include positioning a resilient boot around a rail andthen installing the resilient boot and rail into the shaped trough,wherein the resilient boot has a lateral projection to engage thelateral recess of the shaped trough under the upper shoulder, andwherein the resilient boot is impeded from being disengaged from theprecast slab.

[0009] Additional advantages of the present invention will becomereadily apparent from the following discussion, particularly when takentogether with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is a front perspective view of a completed concrete slab ofthe present invention;

[0011]FIG. 2 is a cross-sectional view of the embodiment shown in FIG.1;

[0012]FIG. 3 is a detailed cross-sectional view of one of the two railsshown in FIG. 2; and

[0013]FIG. 4 is an alternate detailed cross-sectional view of one of thetwo rails shown in FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

[0014] While the present invention will be described more fullyhereinafter with reference to the accompanying drawings, in whichparticular embodiments and methods of implantation are shown, it is tobe understood at the outset that persons skilled in the art may modifythe invention herein described while achieving the functions and resultsof this invention. Accordingly, the description which follows is to beunderstood as illustrative and exemplary of specific structures, aspectsand features within the broad scope of the present invention and not aslimiting of such broad scope.

[0015] In general, the present invention is a precast structural slabthat is subsequently fitted with a resilient boot supporting a railroadtrack or mass-transit line. The combined slab/rail system is installedat road intersections, street running track and thus is heavilytraveled. Referring now to FIG. 1, a perspective view of one embodimentof the precast rail support is shown. The present invention may be usedfor a mono-rail track or for a track arrangement having a plurality ofrails. For explanatory purposes, FIG. 1 depicts a two track arrangement.The precast rail support 10 shown in FIG. 1 includes a precast slab 12that is preferably formed of concrete, and more preferably, is formed ofconcrete having structural reinforcement members, such as, withoutlimitation, steel rebar and/or wire mesh reinforcement, carbon fiber, orfiberglass. The precast rail support 10 shown in FIG. 1 includes twosubstantially parallel steel rails 14. Each rail 14 is situated within ashaped trough 16 where the slab material was blocked-out duringmanufacture of the precast slab 12. Each shaped trough 16 is shaped toreceive a resilient boot 18 (not shown in FIG. 1), which in turn, servesas structural support and vibration damping for the rail 14.

[0016] Referring now to FIGS. 2 and 3, a side elevation view of theprecast rail support 10 is shown in FIG. 2, with FIG. 3 illustrating anenlarged view of the left rail of FIG. 2. The shaped trough 16preferably includes at least one lateral recess 20, and more preferably,a plurality of lateral recesses, with at least one lateral recess 20situated on each side of the shaped trough 16. Each lateral recesses 20preferably includes an upper shoulder 22 that serves to providestructural resistance and support for the resilient boot 18 assemblyafter insertion into the shaped trough 16.

[0017] Still referring to FIG. 3, the resilient boot 18 is preferablymade of hard rubber, polymer, plastic or other type of resilientmaterial, which is well known in the art and has a shape that upwardlysupports the rail 14 after the boot 18 and rail 14 combination areinserted into the shaped trough 16. More particularly, the resilientboot 18 includes an interior opening 24 that holds the rail 14. Inaddition, the resilient boot 18 further includes a bottom portion 26.The bottom portion 26 serves to cushion the rail 14 within the shapedtrough 16, thereby assisting with noise reduction and vibrationdampening when the rail is being traversed by an overlying railcar orvehicle. The resilient boot 18 also includes two side support portions28 that are preferably contiguous with bottom portion 26. The sidesupport portions 28 preferably include lateral projections 29 thatinterlock with the lateral recesses 20 of the shaped troughs 16. Theside support portions 28 resist lateral deflection of the rails 14 andfurther assist with noise reduction and vibration dampening when therail 14 is being traversed by an overlying vehicle.

[0018] In a separate aspect of the invention, the side support portions28 of the resilient boot 18 include at least one, and more preferably, aplurality of void spaces 30. In addition to aiding the noise reductionand vibration dampening characteristics of the precast rail support 10,the void spaces 30 allow the resilient boot 18 to be temporarilycompressed during installation of the rail 14 and the boot 18 into theshaped trough 16. This feature allows the combination of the rail 14 andthe resilient boot 18 to be lubricated, and subsequently squeezed andpushed into the shaped trough 16. Upon being pushed to the bottom of theshaped trough 16, the rail 14 and the resilient boot 18 expand to occupythe space of the shaped trough 16, including the lateral recesses 20that are occupied by the lateral projections 29 of the side supportportions 28. As shown in FIGS. 3 and 4, the void spaces 30 can be anyvariety of shapes, number, and orientation.

[0019] Without limiting the scope of this disclosure, in one preferredembodiment the two rail assembly shown in FIG. 1 is prepared in unitshaving a length of approximately 17.5 feet and a width of approximately8.0 feet, with the outer top edge of each shaped trough 16 positionedabout 1.2 feet from the outside top edge of the precast slab 12. Eachshaped trough 16 is about 0.7 feet wide at its top, with about 4.3 feetseparating the inside top edge of each shaped trough 16. In addition,the precast slab 12 has an overall thickness of about 1.2 feet, witheach shaped trough 16 occupying a depth of about 0.6 feet. Each longside edge of the precast slab 12 has a side edge taper of about 0.25inch from top to bottom, with the top of the slab 12 having a narrowerwidth than the bottom of the slab. Each rail is preferably, but notlimited to, about 115 pound A.R.E.A., and the resilient boot 18 ispreferably made of a non-conductive material.

[0020] In a separate aspect of the present invention, a method ofmanufacturing the precast slab 12 is provided and is now described.Initially, the block-outs that form the shaped troughs 16 are boltedinto place with the precast forms that are used to form the precast slab12. The block-outs include recess projections corresponding to the whatwill become the lateral recesses 20 of the shaped troughs. In addition,the recess projections include shoulder projections which correspond towhat will become the upper shoulder 22 of the lateral recesses 20.

[0021] The interior surfaces of the precast forms including the exteriorblock-out surfaces are then oiled or otherwise receive a non-stickcoating. Preferably, the forms are stood on edge during oiling toprevent the buildup of oil during its application. In addition, ifnecessary, the forms are also optionally cleaned prior to oiling todislodge previously adhered concrete. This optional cleaning step ispreferably performed while the form is placed in an upright position.After oiling, the form is placed in a horizontal position if not alreadyin such an orientation, and the reinforcing materials, such as a rebarcage, carbon fiber, etc., is placed into position. In addition, liftingdevices are preferably positioned such that they are cast into theprecast slab 12. Concrete is then added to the forms. This steppreferably includes vibrating and/or otherwise consolidating theconcrete to prevent air voids.

[0022] Preferably, the surface of the concrete is then smoothed in theform using a device such as a screed or a straight edge. In addition, asthe concrete goes into its initial set, the surface may optionally betroweled smooth, with burrs and high spots eliminated. In addition, itis also optional to slightly round what will be the bottom edges.Further optional steps include conducting quality assurance and/orquality control to check for items such as proper dimensioning of theforms prior to adding the concrete to the forms, as well checking properfinishing and flatness to the concrete surface prior to letting theconcrete fully cure. After the concrete is allowed to cure, the form isturned over and all bolts and any accessories are removed from the formsas necessary. Hook cables or lifting means are then attached to thelifting devices, and the precast slab 12 is removed from the forms.Additional optional steps include spraying the cured precast slab 12with a sealer to aid in inhibiting the detrimental impact of potentialfuture environmental influences, such as chloride ions that may contactthe precast slab 12 after salting. The finished slab is then placed intostorage or shipped to a construction site.

[0023] In yet a separate aspect of the present invention, a method ofinstalling the precast rail support 10 is provided. More specifically,installation is initiated by preparing or otherwise ensuring that thesubgrade is prepared to receive the precast rail support 10. The precastslab 12 is then placed onto the prepared subgrade. Next, the rail 14 andthe resilient boot 18 are fitted together. The exterior of the resilientboot 18 is then lubricated, such as by the application of a lubricant,for example grease or soapy water. The lubricated resilient boot 18 withthe rail 14 in place is then downwardly forced into the shaped trough16. Additional optional steps include placing a plurality of precastslabs 12 prior to installation of the resilient boot 18 and rail 14assemblies into the precast slabs 12. In addition, quality assuranceand/or quality control steps may be performed at any point during theinstallation process, to check such items as proper grade, properlubrication, proper insertion of the resilient boot 18 and rail 14assembly into the shaped trough 14, and proper rail alignment, etc.

[0024] The present invention lends itself to easy repair of the rail 14and/or resilient boot 18. Repair is achieved by removing the resilientboot 18 and rail 14 form the shaped trough 16 by grasping the resilientboot 18 and rail 14 combination with equipment and vertically liftingthe resilient boot 18 and rail from the shaped trough 16. Subsequently,a new rail 14 and or resilient boot 18 can be placed back into theshaped trough by lubricating the exterior of the resilient boot 18 andforcing the resilient boot 18 with the rail positioned therein down intothe shaped trough. Thus, repairs can be made to the rail 14 or resilientboot 18 without the destruction of the concrete, and completereplacement of the slab.

[0025] To provide clarity to the drawings, the following is a list ofthe components and associated numbering as found in the drawings: #Component 10 Precast rail support 12 Precast slab 14 Rail 16 Shapedtrough 18 Resilient boot 20 Lateral recess 22 Upper shoulder 24 Interioropening 26 Bottom portion 28 Side support portions 29 Lateral projection30 Void spaces

[0026] While various embodiments of the present invention have beendescribed in detail, it is apparent that modifications and adaptationsof those embodiments will occur to those skilled in the art. However, itis to be expressly understood that such modifications and adaptationsare within the spirit and scope of the present invention, as set forthin the following claims.

1. A precast apparatus for supporting a transportation rail, comprising:a) a substantially monolithic concrete slab including at least oneshaped trough comprising a first lateral recess having an uppershoulder; b) a resilient boot shaped for insertion into said shapedtrough, said resilient boot including a bottom portion and two sidesupport portions, at least one of said side support portions including asubstantially lateral projection that operatively engaged with saidfirst lateral recess to impede vertical travel of said resilient boot;c) a rail positioned within an interior opening in said resilient boot,wherein said resilient boot supports said rail when said resilient bootand said rail are installed within said shaped trough.
 2. The precastapparatus as claimed in claim 1, wherein said shaped trough furthercomprises a second lateral recess having an upper shoulder.
 3. Theprecast apparatus as claimed in claim 1, wherein each of said two sidesupport portions of said resilient boot include a lateral projection. 4.The precast apparatus as claimed in claim 1, wherein said upper shoulderat least partially confines said lateral projection.
 5. The precastapparatus as claimed in claim 1, wherein said bottom portion and saidside support portions of said resilient boot are contiguous.
 6. Theprecast apparatus as claimed in claim 1, wherein said substantiallyconcrete slab includes a plurality of shaped troughs.
 7. The precastapparatus as claimed in claim 1, wherein said resilient boot comprises arubber material.
 8. The precast apparatus as claimed in claim 1, furthercomprising a lifting means for lifting said substantially concrete slab.9. The precast apparatus as claimed in claim 8, wherein said liftingmeans comprises at least one of a lifting hook, an eye-bolt, a strapmaterial, and a rope material.
 10. The precast apparatus of claim 1,wherein said substantially concrete slab further comprises at least oneof a wire mesh material, a carbon fiber material and a fiberglassmaterial.
 11. The precast apparatus of claim 1, further comprising asteel reinforcing member positioned in said substantially concrete slabbelow said resilient boot.
 12. (Cancelled)
 13. (Cancelled) 14.(Cancelled)
 15. (Cancelled)
 16. (Cancelled)
 17. (Cancelled)
 18. A methodof installing a precast rail support apparatus, comprising: a) preparinga subgrade to receive the precast rail support apparatus; b) placing aprecast slab portion of the precast support apparatus onto the preparedsubgrade, the precast slab portion including at least one shaped troughextending along a longitudinal orientation of said precast slab andhaving a lateral recess, the lateral recess further including an uppershoulder; c) positioning a resilient boot around a transportation rail;d) installing said resilient boot and said transportation rail into saidat least one shaped trough by compressing said resilient boot totemporarily reduce the overall size of the resilient boot, the resilientboot having a lateral projection to engage the lateral recess of saidshaped trough under said upper shoulder, wherein said resilient boot isimpeded from being disengaged from said precast slab.
 19. The method ofinstalling as claimed in claim 18, wherein said step of installing theresilient boot and rail further comprises the steps of: lubricating theexterior of the resilient boot; and forcing the resilient boot and raildownward into the shaped trough of the precast slab until said lateralprojection of said resilient boot engages said lateral recess of saidshaped trough.
 20. (Cancelled)
 21. The precast apparatus of claim 1,wherein said resilient boot further comprises at least one aperturepositioned within said resilient boot to facilitate temporarycompression of said resilient boot, wherein said resilient boot can bepositioned within said at least one shaped trough;
 22. The method ofclaim 18, wherein said resilient boot comprises at least one aperturewhich allows said resilient boot to be temporarily compressed duringsaid installing step.